Well drilling bit



s- 6, 1969 c. A. WHITE 3,463,256

WELL DRILLING BIT Filed Nov. 7, 1967 FIG. 6

CLYDE A. WHITE INVENTOR.

F164 FIG. 5 BY 9 2.." QM Q ATTORNEY United States Patent 3,463,256 WELL DRILLING BIT Clyde A. White, 905 Hughes St., Quanah, Tex. 79252 Filed Nov. 7, 1967, Ser. No. 681,221 Int. 'Cl. E21c 13/02; E21b 9/35 US. Cl. 175-412 3 Claims ABSTRACT OF THE DISCLOSURE Certain specific improvements in a bit as hereinafter described which has heretofore been employed for drilling comparatively shallow, small diameter holes in the earth such as shot holes, water wells and the like.

The invention is applicable to a bit as described having a plurality of three circumferentially spaced removable blades which are received in longitudinal channels therefor in peripheral portions of a tubular blade holder having an externally threaded shank portion for engagement with the lower end of a drill pipe. Each of the blades has a short circumferentially extending portion extending laterally outwardly from at least one side thereof, adjacent the upper end of the blade, which fits around the threaded shank portion of the blade holder and overlies a discontinuous upwardly facing external shoulder on the blade holder communicating with the upper ends of the longitudinal channels therein.

An important feature of the invention is that said circumferentially extending portions of the respective blades, which extend laterally outwardly therefrom, adjacent the upper ends of the blades, as above described, are clamped directly between the lower end of the drill pipe and said upwardly facing shoulder on the blade holder.

The invention contemplates an arrangement as described which includes mutually engaging means on the blade holder and the blades, respectively, whereby the blades are clamped securely to the holder, as the holder is advanced relative to the drill pipe, the blades are positively secured against displacement in any direction relative to the holder, and the structure is additionally reinforced so that the bit is characterized by its ruggedness and dependability as well as its efficiency.

This invention relates to a well drilling bit, and it concerns more particularly certain specific improvements in a bit as hereinafter described which has heretofore been employed for drilling comparatively shallow, small diameter holes, commonly referred to as shot holes, in the earth for use in geophysical exploration operations in which explosive charges are placed in such holes and detonated from the surface, and the resulting earth vibrations are recorded by seismograph.

The invention is applicable to a bit as described having a plurality of three circumferentially spaced removable blades which are received in longitudinal channels therefor in peripheral portions of a tubular blade holder having an externally threaded shank portion for engagement with the lower end of a drill pipe. Each of the blades has a short circumferentially extending portion extending laterally outwardly from at least one side thereof, adjacent the upper end of the blade, which fits around the threaded shank portion of the blade holder and overlies a discontinuous upwardly facing external shoulder on the blade holder communicating with the upper ends of the longitudinal channels therein.

According to the usual practice said upper end portion of the blade is externally beveled for clamping engagement by a ring loosely surrounding the shank portion of the blade holder, in opposing relation to the lower end of the drill pipe and said shoulder, said ring being 3,463,256 Patented Aug. 26, 1969 internally beveled on its under side, whereby a downward thrust is applied to the blades relative to the blade holder as the blade holder is advanced relative to the drill pipe, upon tightening the threads thereof, and the blades are rigidly and removably clamped to the blade holder by abutting engagement of their mutually opposing surfaces.

Patent No. 3,326,308, issued to Marvin E. White, and the references cited therein, show hits as above described.

According to this invention said circumferentially extending portions of the respective blades, which extend laterally outwardly therefrom, adjacent the upper ends of the blades, as above described, are not beveled, the above mentioned beveled ring is omitted, and said circumferentially extending portions of the blades are clamped directly between the lower end of the drill pipe and said upwardly facing shoulder on the blade holder.

The invention contemplates an arrangement as described which includes mutually engaging means on the blade holder and the blades, respectively, whereby the blades are clamped securely to the holder, as the holder is advanced relative to the drill pipe, the blades are positively secured against displacement in any direction relative to the holder, and the structure is additionally reinforced so that the bit is characterized by its ruggedness and dependability as well as its efficiency.

The invention will be readily understood by referring to the following description and the accompanying drawing, in which:

FIG. 1 is a. side elevational view of a well drilling bit embodying the invention, showing one of the blades in place and showing fragmentarily the lower end of a drill pipe to which the bit is connected;

FIG. 2 is an elevational view showing the trailing side of one of the blades, relative to the direction of rotation of the bit, in a detached position of the blade;

FIG. 3 is a view similar to FIG. 2 showing the leading, side of the blade;

FIG. 4 is an elevational view showing the radially inwardly facing longitudinal edge of the blade;

FIG. 5 is a view similar to FIG. 4 showing the radially outwardly facing longitudinal edge of the blade; and

FIG. 6 is a bottom plan view of the bit as illustrated in FIG. 1, showing in broken lines another of the blades in its operative position.

Referring to the drawing, the numeral 1 designates 'generallya well drilling bit having the invention incorporated therein, and the numeral 2 indicates the lower end portion of a drill pipe, shown fragmentarily, having the bit 1 connected thereto.

The bit 1 includes a heavy duty tubular blade holder 3 which as shown has a plurality of three longitudinal channels 4 formed in peripheral portions thereof for engagement, respectively, by a like number of blades 6, and has an upwardly extending externally threaded shank portion 7 whereby the blade holder 1 is connected to the drill pipe 2.

The blade holder 3 has a discontinuous upwardly facing external shoulder 8 communicating with the upper ends of the channels 4, for use as hereinafter described.

The blades 6 have circumferentially extending portions 9 which extend laterally outwardly from at least one side thereof, adjacent their upper ends, which in use are positioned between the lower end of the drill pipe 2 and the upwardly facing shoulder 8 on the blade holder 3, in abutting engagement therewith, whereby the blades 6 are clamped to the holder 3, between the drill pipe 2 and the shoulder 8, as the holder 3 is advanced relative to the drill pipe 2, by tightening the threads thereof.

A downward thrust is imparted to the blades 6 relative to the blade holder 3 by the action of the drill pipe 2 as the blade holder 3 is advanced relative thereto, upon 3 tightening the threads thereof, and the blades 6 are rigidly and removably clamped to the blade holder 3, and secured against displacement in any direction, by mutually engaging means on the blades 6 and the blade holder 3 as hereinafter described.

Said mutually engaging means includes a plurality of pins 10, one of which extends transversely of each of the channels 4, between opposite sides thereof, adjacent its lower end.

Each of the pins 10 is slidably engaged by an opposing slot 11 in the corresponding blade 6, radially inwardly thereof, which is inclined upwardly and radially outwardly whereby it guides the blade '6 radially inwardly, in seating engagement with the bottom of the channel 4, as the blade 6 is advanced downwardly relative to the blade holder 3, upon tightening the threads connecting the blade holder 3 to the drill pipe 2.

Said mutually engaging means further includes one or more comparatively short, upwardly and radially outwardly inclined ridges 12, two of which are shown, which are semi-circular in transverse section and are positioned on the rearward side of each of the blades 6, relative to the direction of rotation of the bit 1, radially inwardly of the blade 6, parallel to and above the slot therein.

The ridges 12 are received in corresponding grooves 13 in the adjacent sides of the respective channels 4, in sliding engagement therewith.

The blades 6 are generally planar and the outer longitudinal edges thereof are straight for a major portion of their lengths, as at 14.

The trailing sides of the channels 4, relative to the direction of rotation of the bit 1, advantageously may be built up, as at 15, so that they extend radially outwardly beyond the opposite sides thereof, so that the blades 6 are additionally reinforced during rotation of the bit 1.

The outer longitudinal edges of the blades 6 are thickened on the trailing sides of the blades 6, relative to the direction of rotation of the bit 1, and terminate in radially inwardly facing shoulders 16, substantially coextensive with the length of the channels 4, overlying the trailing sides 15 of the channels 4 and providing closures for the exposed ends of the grooves 13 therein.

The leading edges of the blades 6, relative to the direction of rotation of the bit 1, and movement thereof in a downward direction, advantageously may be provided with carbide or hard metal inserts 17, 18, for digging rock.

The invention may be modified in various ways without departing from the spirit and scope thereof.

I claim:

1. In a well drilling bit having replaceable blades, the combination of a blade holder having a tubular body and having a plurality of circumferentially spaced longitudinal channels formed in peripheral portions thereof, and having an upwardly extending externally threaded shank portion for engagement with a drill Pipe whereby the blade holder is adapted to be connected to said pipe, the blade holder having a discontinuous upwardly facing external shoulder traversing the upper ends of said channels, below said shank portion, a plurality of blades each received in one of said channels, said blades being substantially planar and extending radially outwardly beyond said channels, the outer longitudinal edges of said blades being straight for a major portion of their lengths, the blades extending above and below said channels and the upper end portions of the blades being arcuate and extending laterally, circumferentially of the blade holder, above said upwardly facing shoulder, for abutting engagement with the adjacent end of said pipe, whereby the blades are adapted to be clamped between the blade holder and said pipe, upon tightening the threads whereby the blade holder is connected to said pipe, and mutually engaging means on the blades and the blade holder including a plurality of pins, one of which extends transversely of each of the channels, between opposite sides thereof, adjacent its lower end, and a slot in each of the blades, radially inwardly thereof, in sliding engagement with the corresponding pin, said slot being inclined upwardly and radially outwardly whereby it guides the blade radially inwardly, in seating engagement with the bottom of the channel, as the blade is advanced downwardly relative to the blade holder, upon tightening the threads connecting the blade holder to said pipe.

2. The structure of claim 1, said mutually engaging means further including one or more comparatively short, upwardly and radially outwardly inclined ridges, semicircular in transverse section, positioned on the rearward side of each of the blades, relative to the direction of rotation of the bit, radially inwardly of the blade, parallel to and above the slot therein, and grooves in the adjacent sides of the respective channels, each positioned opposite one of said ridges, in sliding engagement therewith.

3. The structureof claim 2, the outer longitudinal edges of the blades being thickened on the trailing sides of the blades, relative to the direction of rotation of the bit, and terminating in radially inwardly facing shoulders, substantially coextensixe with the length of the channels, overlying the trailing sides of the channels and providing closures for the exposed ends of the grooves therein.

References Cited UNITED STATES PATENTS 2,498,251 2/1950 Creel l4l2 3,075,594 1/1963 Creel -412 3,326,308 6/1967 White 175-413 3,327,794 6/1967 Creel 1754l2 3,336,992 8/1967 White 1754l2 CHARLES E. OCONNELL, Primary Examiner R. E. FAVREAU, Assistant Examiner 

